With the development of the society and technology, people's life standards improve and the large size television and curved-surface television become more and more popular. Correspondingly, the size of the display screen is made larger and larger and the turnover of the large size and curved surface display screen is more and more difficult. Because the display screen is easy to be damaged, it is not realistic that a person lifts a single large size display screen to move somewhere. Therefore, the large size display screens usually have the design of the external back hanging structure used for the turnover by logistics trolleys. That means that the shape and position of the external back hanging structure on the back plate of the different size flat display screen and the different curvature radius display screen might be different. If the different kinds of the logistics trolleys are designed to solve the issue, it will cause many kinds of the logistics trolleys exist and the weaknesses of the wasting cost, the burden of the management and the occupying of the storage space will appear.